Leader of the Liberals (2001–06)

In the 2001 state election, Labor dealt a massive blow to the reformed Coalition, with the Liberal Party winning only three seats in the 89 member Parliament. Watson resigned as leader and with Sheldon being the only other Liberal MP, Quinn became the Liberal Leader by default. Again, the Coalition agreement was torn up after the defeat.

The Liberals negotiated a new Coalition agreement with the Nationals and their new leader, Lawrence Springborg in April 2003. As leader of the junior party, Quinn became Deputy Leader of the Opposition and Shadow Treasurer. He forged a close working relationship with Springborg and made efforts to repair the damaged relationship between the two parties.

During the 2004 election campaign, Quinn worked closely with Springborg, but was criticised by some Liberals for being too subservient to the Nationals Leader. The Coalition again suffered a massive defeat at the hands of the ALP, with the Liberal Party gaining just two additional seats, lifting its representation to five. When the Coalition agreement automatically expired following the election loss, the two parties opted not to renew it. This decision meant that the Liberals lost their status as members of the Official Opposition (this place being taken by the National Party alone).

After the election, Quinn gained some prominence in the wake of the failures of the Government-owned electricity corporation Energex in South East Queensland. The scandal surrounding Dr Jayant Patel also caused considerable damage to the Beattie Government in 2005. The Liberal Party won the two Labor held seats of Chatsworth and Redcliffe in by-elections in August 2005, bringing the Liberal parliamentary representation to seven seats. However, former Brisbane City councillor Michael Caltabiano, who was elected as the Member for Chatsworth, was touted in the media as a likely challenger to Quinn's leadership.

Quinn and his party dismissed suggestions from Lawrence Springborg that the two conservative parties merge as impractical, but the parties did announce the renewal of their Coalition agreement on 28 September 2005, but without Quinn becoming Deputy Leader of the Opposition.

In February 2005, Bob Quinn criticised then-Premier Peter Beattie for failing to support a scheme which would mandate the addition of fluoride to drinking water in Queensland to improve children's dental health.^[3]

In November 2005, Independent Gympie MP Elisa Roberts accused Quinn of attempting to bribe her. Roberts alleged Quinn offered her $60,000 to join the Liberal Party before the next state election, due in February 2007. Three separate investigations conducted by the Queensland Electoral Commission, the Crime and Misconduct Commission and the Queensland Police all found insufficient evidence to prove the bribery allegations, thus clearing Quinn of any wrongdoing.

On 7 August 2006, Quinn was ousted by a vote in the Liberal Party party room, culminating with the unanimous election of Bruce Flegg as his replacement.^[4] On 11 August 2006 he announced that he would not contest the next state election.^[5]

Quinn was also an unsuccessful candidate in 2007 for the Senate vacancy caused by the resignation of former deputy state leader and Quinn's former state parliamentary colleague Santo Santoro.

Quinn is a member of the Local Government Reform Commission.^[6]